Braitenberg et al.'s view that the cerebellum contributes “mechanical efficiency” to multijoint sequences of movement is too narrow to account adequately for results from new anatomical, neurobehavioral, and neuroimaging studies. A broader view is that the cerebellum modulates attention, sensory, motor, and other neural systems in order to accomplish its prime function, which is to learn to predict and prepare for imminent information acquisition, analysis, or action.